A place for a tired old woman to try to figure things out so that the world makes a bit of sense.

Saturday, July 30, 2005

Astronews

Manned space flight (i.e., the shuttle) gets all the glory and most of the press ink. This morning, however, some other astronomical news hit the wires, and the discoveries described are pretty fascinating.

First, scientists using land-based telescopes have discovered another member of our solar system.

Astronomers in the United States have announced the discovery of the 10th planet to orbit our Sun. The largest object found in our Solar System since Neptune was discovered in 1846, it was first seen in 2003 but has only now been confirmed as a planet.

Its discoverers are Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory in Hawaii, and David Rabinowitz of Yale University.

David Rabinowitz told the BBC News website: "It has been a remarkable day and a remarkable year. 2003 UB313 is probably larger than Pluto. It is fainter than Pluto, but three times farther away.

"Brought to the same distance from the Sun as Pluto, it would be brighter. So today, the world knows that Pluto is not unique. There are other Plutos, just farther out in the Solar System where they are a little harder to find."

It was picked up using the Samuel Oschin Telescope at Palomar Observatory and the 8m Gemini North telescope on Mauna Kea."

Equally as interesting is the news that a tiny moon of Saturn actually has an atmosphere. This discovery comes via the Cassini space probe, an international project being managed by NASA/JPL.

NASA's Cassini spacecraft has found a huge cloud of water vapor over the moon's south pole, and warm fractures where evaporating ice probably supplies the vapor cloud. Cassini has also confirmed Enceladus is the major source of Saturn's largest ring, the E-ring.

Cassini flew within 175 kilometers (109 miles) of Enceladus on July 14. Data collected during that flyby confirm an extended and dynamic atmosphere. This atmosphere was first detected by the magnetometer during a distant flyby earlier this year.

The ion and neutral mass spectrometer and the ultraviolet imaging spectrograph found the atmosphere contains water vapor. The mass spectrometer found the water vapor comprises about 65 percent of the atmosphere, with molecular hydrogen at about 20 percent. The rest is mostly carbon dioxide and some combination of molecular nitrogen and carbon monoxide. The variation of water vapor density with altitude suggests the water vapor may come from a localized source comparable to a geothermal hot spot. The ultraviolet results strongly suggest a local vapor cloud.

The fact the atmosphere persists on this low-gravity world, instead of instantly escaping into space, suggests the moon is geologically active enough to replenish the water vapor at a slow continuous rate.

While I always get caught up in the excitement of a shuttle launch, I think we have gotten more scientific bang for our buck from these unmanned projects. Budgetary constraints and worries about the safety of the aging shuttle fleet makes me think we really ought to shelve the shuttle program for the time being. If this Administration and NASA really are committed to a manned flight to Mars, they ought to find a way to fund it specifically without it cutting into these purely scientific outreaches.

That having been said, I sincerely hope that the current shuttle crew safely complete their mission, and that they come home as the heroes they surely are.